Crystalline Mesoporous Complex Oxides: Porosity‐Controlled Electromagnetic Response
Crystalline Mesoporous Complex Oxides: Porosity‐Controlled Electromagnetic Response
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结晶介孔复合氧化物：孔隙率控制的电磁响应
DOI：
10.1002/adfm.201909491
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发表时间：
2020-02
影响因子：
19
通讯作者：
Lei Jin;Xingsong Su;Jianhang Shi;Kuo-Chih Shih;Daniel Cintron;Tong Cai;M. Nieh;Ou Chen;S. Suib;Menka Jain;Jie He
中科院分区：
文献类型：
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作者：
Lei Jin;Xingsong Su;Jianhang Shi;Kuo-Chih Shih;Daniel Cintron;Tong Cai;M. Nieh;Ou Chen;S. Suib;Menka Jain;Jie He
采用胶体-两亲性模板生长法制备了具有高度晶型骨架的介孔复合氧化物。含有有机硅烷的胶体模板可以转化为热稳定的二氧化硅，防止晶体颗粒过度生长和介孔的崩溃。以钛铁矿CoTiO_3为例，证明了其介孔材料具有较高的结晶度和极高的热稳定性，在800℃空气中保温48h。该合成方法适用于一系列未见报道的介孔、结晶度较高的复合氧化物，如NiTiO_3、FeTiO_3、ZnTiO_3、Co_2TiO_4、Zn_2TiO_4、MgTi_2O_5和FeTi_2O_5等。这些新材料使建立中尺度孔隙率与表面敏感物理化学性质(例如电磁响应)之间的关联成为可能。介孔CoTiO_3的反铁磁有序化温度比无孔CoTiO_3提高了3K。这一发现为设计介孔复合氧化物提供了一般指导，使其能够探索其不同于块体材料的独特性质。
A colloidal‐amphiphile‐templated growth is developed to synthesize mesoporous complex oxides with highly crystalline frameworks. Organosilane‐containing colloidal templates can convert into thermally stable silica that prevents the overgrowth of crystalline grains and the collapse of the mesoporosity. Using ilmenite CoTiO3 as an example, the high crystallinity and the extraordinary thermal stability of its mesoporosity are demonstrated at 800 °C for 48 h under air. This synthetic approach is general and applicable to a series of complex oxides that are not reported with mesoporosity and high crystallinity, such as NiTiO3, FeTiO3, ZnTiO3, Co2TiO4, Zn2TiO4, MgTi2O5, and FeTi2O5. Those novel materials make it possible to build up correlations between mesoscale porosity and surface‐sensitive physicochemical properties, e.g., electromagnetic response. For mesoporous CoTiO3, there is a 3 K increase of its antiferromagnetic ordering temperature, compared with that of nonporous one. This finding provides a general guideline to design mesoporous complex oxides that allow exploring their unique properties different from bulk materials.